Random number generators are widely used in the field of electronics and in electronic devices. Especially when the electronic device is subject to startup the random number generator should provide unpredictable numbers within a fairly short response time. Simple random number generators typically implement pseudorandom number generator circuits or true random number generator circuits based on noise. The choice of the random number generating circuit is however important to fulfill security requirements of various electronic applications.
The random number generator circuit has to be configured to consume as low power as possible and to be testable in reasonable time. Conventional random number generators that feature a large and hence sufficient degree of randomness make use of a memory function, wherein a seed number is stored in a memory during shutdown of the random number generator or of the respective electronic device. Upon startup, the stored number is read and hence recovered from the memory. While such a random seed storage provides sufficient randomness the write and read operation comes along with non-negligible power consumption. Moreover, the read and write procedures are quite time intensive and therefore introduce a certain time delay.